Measuring instrument



K. LAUER.

MEASURING INSTRUMENT.

APPLICATION FILED Nov.s, 1920.

Patented Feb; 7, 1922.

UNITED sTA'rEs PATENT OFFICL f KARL LAUEE, orA xARLsxoqa, SWEDEN, vAssIeNon To FRIED. xnUrPAxTIENGEsELL- SCHAET, F -EssEN-oN-T'HE-EUHR, GERMANY. y'

vMEAsuEINe INSTRUMENT.

lspeifieaeon of rettersratent. Patented Feb, 7, 1922 Application vfiled November 6, `19207. y Serial No. 422,376'.

To all whom it may concern: t Y

Be it known that I, KARL LAUER, residing at Karlskoga, Sweden, a-citizen ofthe German Republic,have `invented Va certain new and useful Improvement in Measuring In .An embodiment ofthe subject matter ofthe invention is illustratedv by 'way of ex- Y Vample in thejanne'xedfdrawing 'in which: A

Fig 41 is ,a longitudinallmidsecti'on "of a caliper gauge, with somep'a'rts broken'away, Fig.y 2 a corresponding top view, partly in section, Fig. 3 isa means, and

Fig. 4 is a -detail .perspective view. Referring to the drawing, at ltheorie extremity of the semicircula'r limb A of the caliper gauge (Fig. 1) there is arranged a cylindrical hole a1, the V,axis of which is parallel to the diameter` terminating the semi-circle formedfby the limb A. Within the hole a1 there is lodged Vto rotate but not to Vshift a substantially cylindrical body detail of the index mounting B. This latter is providedwith la hole b1 disposed axially within which arbolt C is` adapted to be displaced. `The extent to which the bolt C may be displaced is limited by the end faces b2 and d1 of va cylindrical hole'vand of a screw D Iscrewed therein,

endif",

against which latter 'the bolt C -,is adapted to bear by means of a collar c1. The bolt C is provided with anend-portionc2 proj ecting through a hole formedin the screw D,

into the interior ofthe limb Anf the caliper p lsaid portion c2 hei/Dg With its front for its part constitutinga measuring disposed'to the correov-f abolt `(notshovvn) secured lto the other endof vthe semicircular limb A. Hence, the bolt @forms the disgauge;

Surface, Oppositely `placeable ,measuring belli Qf the 'caliper Aure of length, say, forexa'mple, .The scale b1? is arranged within "the l.1.1.1l9lriro1' `gether with the point gauge. At its inner end, the bolt G'isvprovided with a .conical'hole c* into which-the conical point e1 of a bolt is'causedto project. This bolt E terminates at its'then y Vend in a two-pronged fork, the prngs e2 ofl which are provided withknife-edges e3 e* short distance remotefrom Yand parallel-to the knife-edges e3 and e4, 'there vare arranged,

`,disposed along alstr'aiglitV line..` At 'avery two supplemental .knife-edges' b3 and'b,

likewise disposed along a ystraight line and mounted'on an element '67 having two wedgeshaped members and-'66. VThe element 127 is fixed by screws to .the -inside wall of a hollow cylindrical body B? ydisposed coaxially tothe body B,and rigidly Vconne :ted thereto. Into y'the small 'gapfformedbetween the knife-edges e?, e* and fb?, bi1, projects a very *thinV and .perfectlyl Vlevel {shieet F fof the 'shape disclosed' more "particularly ner shown in the Adrawing by ymeans" of two screws g3. 'In thesfheetjF there is f r' II 1/ed a hole)f1 into whichis slipped theorie endVA of a tension spring H, the opposite',V end ,of which engages an eye vb9 securedv to the l.b ofly B. "Within the members GF, QG," there are formed slots 'gt g' of the kind disclosed -in the drawing through which the one -end of ,the spring can pass. -By means ,of the tension spring H, the Yblock G, G1, /Gz is forced, `at its corners formed by the projecting yportion of the `sheet 'Riagainst "the knife-,edges b3, b4 and e3, e4. this ar- .rangement the bolt l pension as yclearly vlshown 'in f1. To the ,bloc-k del, e2 Ythere sexes an index J consisting of a tongueshaped metal strip; the endo-f said index, when in the position shown in Fig. 1 pointsfto Zero of ga' scale `b1" `(Fig. l). Each division marked onthe scale b1 corresponds to a' very minute Ineas- Offthe body B8 andimay be observed; t0,-

p of the index through .Sight-Opening' If*- v-The index@ .femmine the movable element 'of the-indicating device, .togetherfwith the block 1G, "SG1, U'G

E is maintaijne'd in /susof two notches established by the projecting of the sheet F, between the knife-edges o, b* and e3, e4. i

In use, the caliperl gauge is applied to the body'to be measured in sucha Vmanner that the measuring surface o3 as well as the corresponding surface of the oppositely disposed bolt (not shown), will touch the exterior of the surface of the body to be measured. lIn the vevent of the dimension of this bod Y proving to be somewhat larger than `the distance existing intermediate the said measuring surfaces, then the bolt C is slightly displaced in the direction indicated by the arrow in Fig. l. The bolt E,

yheld in suspension'by the tension spring H, participates in this displacement and the knife-edges es, e4, arranged at the prongl shaped ends e2 cause the sheet F and there- "indicated by the arrow g/ (Fig. l) against the action of the spring H about the stationary knife-edges b3, b4 forming an axis of rotation. The magnitude of this rotatory motion is roportional to the displacement the bolt is subjected to. The fact is that the4 deflection of the index relatively to the displacement of the bolt C is proportional to the length of the index, measured j from the axis of-rotation, relatively to the L thickness ofthe sheet F. In accordance herewith the scale b1 is so devised that the position assumed by the index J relatively to said scale 51 will directly indicate the magnitude of the displacement carried out by the bolt C. As soon as the caliper gauge is removed lfrom the body to be measured, the vmovable parts of the instrument, now acted upon yby the tension spring H, return into their respective initial positions shown by the drawing, in which the collar c1 of the bolt C bears up against the front end (Z1 of the screw D.

vSince the deflection of the index merely depends upon the length of the index and the thickness of the sheet F, and these two magnitudes can be secured at the desired amount from the very outset and with .utmost accuracy without any difficulty, there is no need of providing the measuring instruments, constructed on the lines of this invention, with any special adjusting equipments adapted to change the deflection of the index for the purpose of setting the instrument. It will thus be clearly seen that the construction of the present measuring instrument is far Isimpler than that of the measuring instrumentsv provided with the aforesaid adjusting equipment and.Y as hitherto known. Since, moreover, the

notches of the block supporting the index v"J are established by a sheet ground down v ,l to a most accurate dimension being causedl to project beyond the said block there are subject matter of this-invention consequently excels by virtue of a form of construction adapted to warrant a particularly delicate measuring capacity. Further, the arrangement of the two notches symmetrically to 76 the tension spring H yields the advantage of the block being forced against the knifeedges b3, b4 and'e, @4in a perfectly uniform manner. Finally, by the provision of the slots g4, g5, the possibility is provided of disposing the oint of application of thevtension spring #l as closely as possible tothe axis of rotation ofthe index J, formed by the stationary knife-edges b3, b4. AThe travel of the spring is thus reduced to a particularly small extent. It is this fact, however, which augments its usefulness for continuous service, asvthen the tension of the spring will remain much longer uniform than if it were obliged to travel for a considerable distance inthe course of each measuring operation.

Claims: v l

l. In a measuring instrument provided with a reading-olf device, a lever forming the movable part of said reading-off device, a spring connected to'said lever and to the body of the measuring instrument tending to draw saiid lever-into its normal position, knife edges forming bearings for said lever, said knife edges being supported by the measuring instrument body and a displaceable bolt, and a plate secured to said lever and forming therewith bearing faces to receive said knife edges.

2. In a measuring instrument provided with a reading-off device and a body portion, a lever forming'thegmovable part of said reading-oil device, a spring connected to said body and tosaid lever and tending to draw said leverintoits zero position, knife edges forming bearings for said lever and arranged in forli-like manner, said knifeedges being supported by said Abody and a boltniovable inl said body res aectively, bearing faces on sail lever adapted to receive said knife edges, said bearing faces being formed lby a thin sheet of metal projecting beyond the body of said lever, said spring Y being attached to said lever at a point situ- 120 ated between said fork-like knife edges. v

3. In al measuring instrument provided with a reading-off device and a displaceable bolt, a body portion,v alever within said body and forming the movable part of said 125 reading-olli' device, spring means connected to said lever and said body 'tending to draw said lever into its zero position, knife edges secured to said body and to said displaceable bolt and forming bearings -for said lever, 13o

said lever being formed with an enlarged body portion, bearing faces .on said lever body adapted to receive said knife edges, said bearing faces being formed by a thin sheet of metal projecting beyond said body portion said spring being attached to said sheet of metal.

el. In a measuring instrument having a body, a reading-off device and a displaceable bolt, a leve-r provided With an enlarged body portion and forming the movable part of said reading-off device, a spring connected to said lever and to said body tending to draw said lever into its zero position, knife edges forming bearings for said lever, said knife edges being secured to said body and displaceable bolt respectively, said lever being formed With bearing faces to receive said knife edges, said bearing faces being formed' b-y a thin sheet of meltal projecting beyond the body of said lever, said spring being attached to said sheet of metal at a point situated between said knife edges.

5. In a. measuring instrument provided with'bearing faces for the reception of said knife edges, a thin sheet of metal secured to said lever body and projecting therebeyond forming said vbearing faces, said spring being attached to said sheet of metal at a point situated between said knife edges and in close proximity to the axis of rotation of said lever.

The foregoing specification signed at Stockholm, Sweden, this 11 day of October,

KARL LAUER. In presence of- P. A. HERNELL,

G. SJAGREN. ffl 

